MTN UNHELPFUL!

I have an mtn anytime 100 contract with MTN for the last 18 years.I have always been able to convert my airtime that I load to data, but for this last month I have not been able to do that. I tried again sunday morning the 21st Feb 2016 and I still couldnt convert to data. I contacted MTN on *** & was given a reference number and told that they would sort it out within 48hours & I must not load anymore airtime or data until they contact me. No one has contacted me thus far.On Wednesday morning the 24th Feb I contacted them again & spoke to a lady. They said it is still being investigated. I asked for the person dealing with the complaint & they said this person was unavailble. I then called again and my call was dropped. I was then told this issue was resolved on the sunday the 21st. Several times I tried to get a hold of the person dealing with it or a supervisor but they ended my call. i have made between 12 & 15 calls to MTN yesterday & today but no change..Between the call centre & technical dept, no one seems to know how to fix this & this is inconvenciencing me greatly. I am greatly diappointed with MTN as this is now affecting my business affairs.